I have a project being setup in my garden for an aeroponics system its basic components are: 1. Esp8266 2. Single channel relay board 3. Temperature & humidity sensor 4. 12v 3a - 100psi pump 5. 2 x 12v 12ah batteries
I now want to add a charger and solar panel to maintain the power on this system or atleast reduce charge frequency as much as practically possible.
My setup will be 30 seconds every 2 minutes the pump turns on, the pump is 36 watts I'm overestimating the rest of the system to say 2.5 watts so we are possibly looking at using 38.5 watts for 30 seconds every 2 minutes.
Now a 40 watt solar panel is incredibly expensive for what I'm using it for and I have looked at the 4.5 watt version but how do I work out the correct panel I need.
Is there a proper way to do this? I just calculated it will have the pump running for 3.4 hours in a 24 hour period.